Method for manufacturing recycled resin raw materials, method for manufacturing recycled film, and apparatus for processing resin film

Abstract

The present invention provides a method for producing recycled resin raw materials with minimal foreign matter contamination. [Solution] The method for manufacturing recycled resin raw material includes preparing a roll on which a resin film joined with splice tape is wound, unwinding the resin film from the roll, removing the splice tape from the resin film unwinding from the roll, removing the printed layer contained in the resin film from which the splice tape has been removed, and manufacturing recycled resin raw material using the resin film from which the printed layer has been removed as a starting material.

Description

Technical Field

[0001] The present invention relates to a method for producing a recycled resin raw material, a method for producing a recycled film, and a resin film processing apparatus.

Background Art

[0002] Patent Document 1 discloses a technique for recycling a recycled resin raw material from a roll-shaped resin film such as end materials and unused inventory.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the resin film wound around one film roll is not always a seamless single piece. Rather, in many cases, it is interrupted in the middle, and the interrupted part is joined with a splice tape such as an aluminum tape or a colored vinyl tape. This is due to circumstances such as a portion where problems such as printing defects have occurred in the resin film being cut out, or the length of the resin film to be wound around the film roll being short. And when producing a recycled resin raw material from such a film roll, the splice tape may be mixed into the recycled resin raw material as a foreign substance, and the quality of the recycled resin raw material may deteriorate.

[0005] An object of the present invention is to produce a recycled resin raw material with less foreign matter inclusion. Another object of the present invention is to produce a recycled film with less foreign matter inclusion using such a recycled resin raw material. Still another object of the present invention is to provide a resin film processing apparatus suitable for producing such a recycled resin raw material.

Means for Solving the Problems

[0006] Item 1. Prepare a roll of resin film joined with splice tape, The process of unwinding the resin film from the roll, Removing the splice tape from the resin film unwound from the roll, The process involves removing the printed layer contained in the resin film from which the splice tape has been removed, The resin film from which the printing layer has been removed is used as a starting material to produce recycled resin raw material. A method for producing recycled resin raw materials, including

[0007] Item 2. Connecting the separated ends of the resin film that have been separated by the removal of the splice tape. It further includes, Removing the printed layer means removing the printed layer from the resin film to which the separated ends are connected. A method for producing recycled resin raw materials as described in item 1.

[0008] Item 3. Connecting the separated ends includes joining the separated ends with a resin tape. A method for producing recycled resin raw materials as described in item 2.

[0009] Item 4. The resin film and the resin tape are heat-shrinkable films. A method for producing recycled resin raw materials as described in item 3.

[0010] Item 5. Removing the splice tape is, The position of the splice tape contained in the resin film is detected, Based on the detected position, the splice tape is removed from the resin film. including, A method for producing recycled resin raw materials as described in any of items 1 to 4.

[0011] Item 6. The splice tape is an aluminum tape or a colored vinyl tape. The method for producing a recycled resin raw material according to any one of Items 1 to 5.

[0012] Item 7. Manufacturing a recycled film using, as at least a part of the raw material, the recycled resin raw material produced by the manufacturing method according to any one of Items 1 to 6. A method for manufacturing a recycled film, including this.

[0013] Item 8. A pay-out unit that pays out the resin film from a roll around which the resin film joined by a splice tape is wound, A removal unit that removes the splice tape from the resin film paid out from the roll, A deinking unit that removes the printing layer contained in the resin film from which the splice tape has been removed A processing apparatus for a resin film, comprising this.

Advantages of the Invention

[0014] According to the present invention, it is possible to produce a recycled resin raw material with less foreign matter contamination. Further, it is possible to produce a recycled film with less foreign matter contamination using such a recycled resin raw material. Further, a processing apparatus for a resin film suitable for producing such a recycled resin raw material is provided.

Brief Description of the Drawings

[0015] [Figure 1] A block diagram schematically showing a resource recycling system according to an embodiment. [Figure 2] A cross-sectional view of a waste film according to an embodiment. [Figure 3] A diagram showing an example of a removal apparatus according to an embodiment. [Figure 4] A plan view showing an example of a first processing apparatus included in the removal apparatus of FIG. 3. [Figure 5] A side cross-sectional view showing a method for removing a splice tape according to a modification.

Modes for Carrying Out the Invention

[0016] One embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. Furthermore, the drawings are schematic representations, with parts omitted or exaggerated as appropriate, for ease of understanding.

[0017] [1. Configuration of the Resource Recycling System] In recent years, marine pollution caused by plastic waste has become a global problem. Resource recycling is attracting attention as a means of addressing such problems. Figure 1 is a schematic diagram of a resource recycling system S1 that uses the manufacturing method of recycled resin raw material 3 and the manufacturing method of recycled film 4 according to this embodiment. As shown in Figure 1, in the resource recycling system S1, waste resin film (hereinafter referred to as "waste film") 1 is recycled and recycled resin raw material 3 is manufactured. Various resin products can be manufactured from the recycled resin raw material 3, for example, new resin film (hereinafter referred to as "recycled film") 4 can be manufactured. Waste film 1 is a packaging material in the form of film or label that can be used in various fields such as food, beverages, pharmaceuticals, medical products, chemicals, cosmetics, toiletries, industrial products, and agricultural products. Recycled film 4 can also be a similar packaging material.

[0018] Although not limited to this, the waste film 1 is, for example, a heat-shrinkable film in its state before heat shrinkage. In this case, the waste film 1 may be, for example, a uniaxially oriented film that shrinks mainly in the width direction, i.e., in the TD (Transverse Direction). The heat shrinkage rate of the waste film 1 in the main shrinkage direction can be appropriately selected depending on the application, but it is preferably 30% or more, and more preferably 50% or more, when immersed in 90°C hot water for 10 seconds.

[0019] Figure 2 is a cross-sectional view of the waste film 1 according to this embodiment. The waste film 1 has a resin film body 11 and functional layers 12 and 13 laminated on both sides of the film body 11, respectively. The film body 11 is a transparent or translucent resin film, although it is not limited to this. The functional layers 12 and 13 are, for example, a printing layer, a matte layer, a protective layer (e.g., an overcoat layer, a hardcoat layer, etc.), a smooth layer (e.g., an innercoat layer, an antiblocking layer, etc.), a barrier layer, a light-shielding layer, an ultraviolet-absorbing layer, a metal film, an easy-adhesion layer, a release layer, an antistatic layer, a conductive layer, etc. Of these, the printing layer is a layer for applying a pattern to the film body 11 and contains a coloring component (colorant) such as ink. The pattern is composed of, for example, a design, letters, symbols (e.g., a barcode), or a combination thereof. The printed layer is formed, for example, by printing with oil-based or water-based ink using an intaglio plate (gravure plate, etc.), a relief plate (flexographic plate, etc.), a planographic plate (offset plate, etc.), or a stencil plate, or by digital printing such as an inkjet method.

[0020] The waste film 1 can be, for example, unused products, scraps, intermediate processed products, leftovers, defective products, prototypes, or discarded products. The waste film 1 can be, for example, a product film having a product portion used for packaging the target product and a film edge continuous with the edge of the product portion. Alternatively, the waste film 1 can be, for example, a product portion cut from such a product film, a film edge, or a lead film used for printing registration (pattern alignment). The film edge is separated from the product portion by cutting the product film along the boundary line between the product portion and the film edge before the product portion is shipped. The product portion includes a printed layer, which is, for example, a functional layer 12, 13 on which information about the target product to be packaged by the product portion is printed. The film edge includes a printed layer, which is, for example, a functional layer 12, 13 on which information for checking the printing status in the product portion is printed. The product portion can be, for example, used for packaging various containers such as plastic containers, glass containers, and paper containers. If the product portion is a heat-shrinkable film, it shrinks when heated and is attached to the container by, for example, conforming to the outer surface of the container along its outer shape. The product portion is, for example, formed into a cylindrical shape, placed over the container so as to cover it from the outside, then heat-shrinked and attached to the container. The product portion is formed into a cylindrical shape by, for example, overlapping both ends of the TD and sealing the overlapped portion in the MD (Machine Direction) by applying an adhesive or solvent. In this case, when the product portion is attached to the container as a label, typically the TD of the product portion corresponds to the lateral direction of the container, and the MD of the product portion corresponds to the longitudinal direction of the container.

[0021] The thickness of the film body 11 is not particularly limited and can be appropriately selected depending on the application, but is preferably 10 μm or more, more preferably 12 μm or more, and even more preferably 15 μm or more. Furthermore, the thickness of the film body 11 is preferably 60 μm or less, more preferably 50 μm or less, and even more preferably 40 μm or less. The film body 11 may be a single layer or a multilayer. The film body 11 may contain layers mixed with different types of resin. Furthermore, the film body 11 may contain multiple layers, each containing a different type of resin. Furthermore, each layer constituting the film body 11 may contain components other than resin. Each layer constituting the film body 11 may contain various additives. Examples of additives include antiblocking agents, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, antistatic agents, flame retardants, antibacterial agents, and fluorescent whitening agents.

[0022] Examples of resin types contained in the film body 11 include polyolefin resins, polystyrene resins, polyamide resins, and polyester resins. Examples of polyolefin resins include polypropylene, polyethylene, and cyclic polyolefin resins. Examples of polystyrene resins include styrene homopolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-isoprene-butadiene copolymers, styrene-acrylic copolymers, acrylonitrile-butadiene-styrene copolymers, and acrylonitrile-styrene copolymers. Examples of polyamide resins include aliphatic polyamides such as nylon 6 resins, nylon 66 resins, and nylon 12 resins, as well as aromatic polyamides, amorphous polyamides, and polyamide elastomers. Examples of polyester resins include those obtained by condensation polymerization of a dicarboxylic acid component and a diol component. The types of dicarboxylic acid components mentioned above are not particularly limited, and examples include terephthalic acid, o-phthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, decamethylenecarboxylic acid, their anhydrides, and lower alkyl esters.The types of diol components listed above are not particularly limited, and include ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5- Examples include aliphatic diols such as hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, and polytetramethylene ether glycol; 2,2-bis(4-hydroxycyclohexyl)propane; alkylene oxide adducts of 2,2-bis(4-hydroxycyclohexyl)propane; and alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol.

[0023] The thickness of each of the functional layers 12 and 13 is not particularly limited and can be appropriately selected depending on the application, but is preferably 0.1 μm or more and 5.0 μm or less, more preferably 0.3 μm or more and 4.0 μm or less, and even more preferably 0.5 μm or more and 3.0 μm or less. Each of the functional layers 12 and 13 may be a single layer or a multilayer. The functional layers 12 and 13 may be the same type of layer or different types of layers. For example, functional layer 12 may consist of a printing layer laminated on the back surface of the film body 11 and an inner coat layer laminated on the printing layer, and functional layer 13 may consist of an overcoat layer laminated on the front surface of the film body 11. Here, the back surface refers to the inner surface that faces the product when the product is packaged, and the front surface refers to the outer surface on the opposite side. The printing layer is composed of, for example, a coloring component (colorant) such as ink that forms a pattern. The printing layer may be a single layer or a multilayer. The inner coat layer is formed, for example, to improve the slipperiness between the target product and the labeling device that attaches the film as a label to the target product. The overcoat layer is formed, for example, to reduce scratches on the outward-facing surface of the label attached to the target product. The inner coat layer and the overcoat layer are each formed, for example, in the pattern printing process.

[0024] The waste film 1 is a long piece of film that is wound up for storage and handling purposes and managed in the form of a film roll (winding body) R1. The waste film 1 wound on a single film roll R1 is not necessarily a single, seamless piece, but is often broken in the middle, and the broken parts are joined with splice tape 5. In other words, the film roll R1 is wound with multiple pieces of waste film 1 that have been joined together with splice tape 5 to make them longer. This is due to circumstances such as the removal of parts of the resin film where printing defects or other problems occurred, or the length of the resin film intended to be wound on the film roll R1 being too short. The splice tape 5 is an adhesive tape that has an adhesive layer and can be attached to the resin film, such as aluminum tape or colored vinyl tape.

[0025] Referring again to Figure 1, the resource recycling system S1 comprises a removal device 10, a recycled resin raw material 3 manufacturing device 20, and a film manufacturing device 30. Figure 3 shows an example of the removal device 10. In terms of how to use the removal device 10, first, a film roll R1 on which the waste film 1 is wound is prepared and set in the removal device 10. Next, the waste film 1 is unwound from the film roll R1, the unwound waste film 1 is processed, and a processed film 2 is produced. The processed film 2 is obtained by removing the splice tape 5 and functional layers 12 and 13 from the waste film 1. Although not limited to this, in this embodiment, the removal device 10 is a device that processes the resin film while conveying it roll to roll.

[0026] As shown in Figure 3, the removal device 10 comprises a first processing device 40 and a second processing device 50. The first processing device 40 is a device that removes the splice tape 5 from the waste film 1 unwound from the film roll R1. When the splice tape 5 is removed by the first processing device 40, the waste film 1 is broken at the location where the splice tape 5 was attached. However, in this embodiment, the broken portion of the waste film 1 is reconnected by the sealer 430 (see Figure 4) included in the first processing device 40. Therefore, the processed film 2 also becomes a long film similar to the waste film 1. The second processing device 50 removes the functional layers 12 and 13 from the waste film 1 from which the splice tape 5 has been removed. The functional layers 12 and 13, in particular the printed layers included in the functional layers 12 and 13, are removed in order to prevent a decrease in the functionality of the recycled resin raw material 3 and the recycled film 4 manufactured from the recycled resin raw material 3 by mixing them with the recycled resin raw material 3. The processed film 2 typically consists only of the film body 11 and does not have the functional layers 12 and 13, although some of the functional layers 12 and 13 may remain.

[0027] The removal device 10 further comprises a control unit 100 that controls the operation of each part of the removal device 10 (including the processing devices 40 and 50). The control unit 100 consists of a CPU (Central Processing Unit) and a storage device, etc.

[0028] In the resource recycling system S1, the manufacturing device 20 further produces recycled resin raw material 3 from the processed film 2. The manufacturing device 20 uses the processed film 2 produced by the removal device 10 as the starting material to produce recycled resin raw material 3. Recycled resin raw material 3 is a resin raw material obtained by processing the processed film 2 into a shape that is easy to handle when producing recycled film 4 from the processed film 2. Specifically, recycled resin raw material 3 can be in the form of fluff 3a, pellets 3b, powder 3c, granules 3d, etc. There is a type of pellet 3b that is produced by heating and melting the raw material and then solidifying it, but granules 3d are different from such types of pellets 3b; they are lumps that are compressed and solidified without heating and melting the powdered raw material. Furthermore, recycled resin raw materials 3, such as fluff 3a, powder 3c, or granules 3d, which are manufactured without heating and melting the raw materials, may be more susceptible to thermal degradation than recycled resin raw materials 3, such as the pellets 3b described above, which are manufactured by heating and melting the raw materials and then solidifying them, because they do not undergo excessive thermal history such as heating and melting during processing.

[0029] The processed film 2 can be processed into fluff 3a by, for example, using a known crusher, shredder, cutter, etc., to finely chop the processed film 2. The size (area) of fluff 3a is 500 mm². 2 The following is preferable: 300mm 2 The following is more preferable: 200mm 2 The following is even more preferable: 100 mm 2 The following are particularly preferable.

[0030] The processed film 2 can be processed into pellets 3b using, for example, a known resin pellet manufacturing machine. For example, fluff 3a can be supplied to an extruder, heated and melted in the extruder, then extruded through a die, and the extruded material can be cut into an appropriate shape to produce pellets 3b. Note that pellets 3b may be manufactured not only from the processed film 2 (fluff 3a) but also from virgin resin raw materials and / or chemically recycled resin raw materials (hereinafter referred to as virgin resin raw materials, etc.). In this case, virgin resin raw materials, etc., are supplied to the extruder in addition to fluff 3a. This method yields pellets 3b of a type created by heating, melting, and then solidifying the raw materials.

[0031] Another method for processing into pellets 3b is as follows: The narrow processed film 2, which is the film edge, is unwound from the roll, and a single film edge or a bundle of multiple film edges is twisted by rotating it parallel to the conveying direction. After the twisted film edge is compressed, it is cut to a predetermined size. In this method, pellets 3b are produced without heating and melting the raw material.

[0032] The processed film 2 can be processed into powder 3c by, for example, the following method. First, the fluff 3a is immersed in a suitable solvent to dissolve the resin components contained in the fluff 3a in the solvent, thereby generating a solution containing the resin components. Then, the resin components are precipitated by cooling the solution, mixing it with a poor solvent, and / or heating the solution to evaporate the solvent. After that, the precipitated resin components is dried to produce powder 3c.

[0033] The processed film 2 can be processed into granules 3d, for example, by drying the resin component precipitates described above while stirring them under vacuum. Alternatively, the granules 3d can also be manufactured using a known granulator. In this case, the resin component precipitates or powder 3c described above can be fed into the granulator.

[0034] In the resource recycling system S1, recycled film 4 is further manufactured from recycled resin raw material 3 by the film manufacturing apparatus 30. The film manufacturing apparatus 30 manufactures recycled film 4 using the recycled resin raw material 3 manufactured by the manufacturing apparatus 20. Known film formation methods can be used as processing methods for recycled film 4. For example, recycled resin raw material 3 may be supplied to an extruder, heated and melted in the extruder, and then extruded from a die. In this case, a laminated film can be manufactured by co-extrusion. After molding, the recycled film 4 may be stretched as appropriate to impart heat shrinkability and processed into a heat shrinkable film. In addition, functional layers such as functional layers 12 and 13 (for example, printed layers) may be appropriately laminated onto the recycled film 4.

[0035] The recycled film 4 may be manufactured using not only recycled resin raw material 3 but also virgin resin raw material, etc. In this case, for example, virgin resin raw material, etc., in addition to recycled resin raw material 3, may also be supplied to the extruder. The recycled film 4 can be constructed in the same way as the film body 11 contained in the waste film 1 in terms of material, layer structure, and thickness, etc. Therefore, the above description of the film body 11 also applies to the recycled film 4. The recycled film 4 may be single-layered or multi-layered. If the recycled film 4 is multi-layered, recycled resin raw material 3 may be used in at least one layer contained in the recycled film 4, and at least another layer may be composed only of virgin resin raw material, etc., among virgin resin raw material, etc. and recycled resin raw material 3. For example, if the recycled film 4 includes an intermediate layer and adjacent layers arranged on both sides of the intermediate layer, the intermediate layer may be composed of a mixture of recycled resin raw material 3 and virgin resin raw material, etc., and the adjacent layers may be composed only of virgin resin raw material, etc., among virgin resin raw material, etc. and recycled resin raw material 3.

[0036] [2. Configuration of the removal device] Referring again to Figure 3, the configuration of the removal device 10 will be described in detail. The removal device 10 includes two processing devices 40 and 50, as well as an unwinding machine 61, a winding machine 62, and guide rollers 60. The unwinding machine 61 is located at the upstream end of the removal device 10 and has a shaft that rotatably holds the film roll R1. When the film roll R1 set on the shaft of the unwinding machine 61 rotates, the waste film 1 is unwound from the unwinding machine 61 and transported downstream. Numerous guide rollers 60 are installed along the transport path. At least some of the guide rollers 60 may be drive rollers. The waste film 1 is transported to the winding machine 62, located at the downstream end of the removal device 10, guided by these guide rollers 60. In the process, the waste film 1 is processed into processed film 2 by passing through the two processing devices 40 and 50. The processed film 2 is wound into the form of a film roll R2 by the winding machine 62. The winding machine 62 has a shaft (typically a drive shaft) that rotatably holds the film roll R2. The unwinding machine 61 and winding machine 62 can be, for example, a twin-shaft turret type. The unwinding machine 61, winding machine 62 and guide roller 60 are a mechanism that feeds and transports the waste film 1 from the film roll R1, and are an example of a feeding section.

[0037] Figure 4 is a plan view of the processing apparatus 40. As shown in the figure, the processing apparatus 40 comprises a detection unit 410, a cutting device 420, and a sealer 430. The detection unit 410 is positioned near the transport path of the waste film 1 and detects the position of the splice tape 5 contained in the waste film 1. For example, the detection unit 410 observes the waste film 1 at a fixed point slightly upstream of the cutting device 420 and detects the position where the splice tape 5 has passed. In this embodiment, the detection unit 410 consists of a camera and a processor that processes the image captured by the camera (which may be integrated with the control unit 100 or be a separate unit), but is not limited to this. For example, if the splice tape 5 is an aluminum tape, the detection unit 410 may consist of a metal detector.

[0038] Upon receiving detection of the splice tape 5's position by the detection unit 410, the control unit 100 drives a cutting device 420 positioned near the transport path of the waste film 1. The cutting device 420 removes the splice tape 5 from the waste film 1 based on the position of the splice tape 5 detected by the detection unit 410. The cutting device 420 is an example of a removal unit. For example, the cutting device 420 cuts the waste film 1 slightly upstream and slightly downstream of the location where the splice tape 5 is attached, in a direction perpendicular to the transport direction (TD). The cutting device 420 can be configured as any mechanism capable of cutting resin film; for example, it may be configured to have a blade, or it may be a laser cutter, etc. As a result, the splice tape 5 is removed from the waste film 1, and the waste film 1 is separated into an upstream side and a downstream side at the location where the splice tape 5 was attached. The splice tape 5 cut from the waste film 1 is collected as appropriate by a suction device, etc. In the example shown in Figure 4, to prevent the waste film 1 from falling off the transport path at the point where the splice tape 5 is cut, holding mechanisms 421 and 422 are positioned near the upstream and downstream sides of the cutting device 420, respectively, to hold the waste film 1 in place. Each of the holding mechanisms 421 and 422 can consist of, for example, a pair of rollers (typically driven rollers) positioned to sandwich the waste film 1.

[0039] The control unit 100 drives the sealer 430 once the cutting device 420 has finished removing the splice tape 5. More specifically, the control unit 100 moves the cutting device 420 away from the vicinity of the transport path and moves the sealer 430 to the vicinity of the transport path instead. In the example in Figure 4, the cutting device 420 and the sealer 430 are connected to the same movable axis, and the sealer 430 moves simultaneously with the retraction of the cutting device 420.

[0040] After being moved near the transport path, the sealer 430 connects the upstream and downstream separated ends of the waste film 1, which has been separated by the removal of the splice tape 5. In this embodiment, the sealer 430 joins the upstream and downstream separated ends of the waste film 1 with a resin tape 6. The resin tape 6 is preferably a tape without an adhesive layer. Although not limited to this, in this embodiment the sealer 430 is an ultrasonic sealer. For example, the sealer 430 overlaps the resin tape 6 on the waste film 1 so as to cover the upstream and downstream separated ends, and then adheres (welds) the resin tape 6 to the portions of the waste film 1 near the upstream and downstream separated ends. This reconnects the broken sections in the waste film 1 via the resin tape 6. At this time, it is preferable to seal in a dashed line (perforated line) rather than a straight line so that the waste film 1 does not tear at the sealing points with the resin tape 6. The sealing locations between the upstream separation end of the waste film 1 and the resin tape 6 may be two or more (two or more rows). The sealing locations between the downstream separation end of the waste film 1 and the resin tape 6 may also be two or more (two or more rows). The resin tape 6 may be supplied to the sealer 430 by being unwound from a roll and cut to an appropriate length in the sealer 430. Alternatively, a large number of resin tapes 6 that have been pre-cut to an appropriate length may be prepared and supplied to the sealer 430 one by one when joining the waste film 1.

[0041] It is preferable that the resin tape 6 is a film containing the same type of resin component as the film body 11 so as not to become a foreign substance to the resin component contained in the waste film 1 which is recycled into recycled resin raw material 3. Furthermore, it is preferable that the resin tape 6 is composed only of the film body and does not have a functional layer (e.g., a printed layer) such as functional layers 12 and 13 laminated on it. Also, if the waste film 1 is a heat-shrinkable film in its pre-heat-shrinkage state, it is preferable that the resin tape 6 is also a heat-shrinkable film in its pre-heat-shrinkage state. In this case, when the waste film 1 joined by the resin tape 6 is heat-shrinked in the subsequent second processing device 50, the resin tape 6 will heat-shrink in accordance with the waste film 1. As a result, the resin tape 6 will be less likely to peel off the waste film 1 as the waste film 1 heat-shrinks, preventing the waste film 1 from being severed again.

[0042] The control unit 100 temporarily stops the transport of the waste film 1 within the first processing device 40 while the cutting device 420 and sealer 430 are operating. The removal device 10 further includes an accumulator 70 positioned between the first processing device 40 and the second processing device 50. The accumulator 70 has a plurality of accumulator rollers around which the waste film 1 is wound, and the amount of waste film 1 stored can be adjusted by raising and lowering these accumulator rollers. As a result, even if the transport of the waste film 1 stops within the first processing device 40, the waste film 1 continues to be transported within the subsequent second processing device 50, allowing the second processing device 50 to continue its operation.

[0043] In the second processing apparatus 50, the splice tape 5 is removed, and instead, the functional layers 12 and 13 are removed from the waste film 1, which is joined with resin tape 6. The second processing apparatus 50 is an example of a deinking unit, and removes, for example, the printed layer contained in the functional layers 12 and 13. The second processing apparatus 50 is configured to remove the functional layers 12 and 13 by physical, chemical, or both methods. Examples of physical methods include removing the functional layers 12 and 13 from the film body 11 by mechanical action such as rubbing, scraping, or peeling using a polishing roller, file, metal rotating brush, rotating blade, scraper, belt sander, blasting device (including wet blasting device), etc. Examples of chemical methods include immersing the waste film 1 in a solution containing a solvent capable of dissolving the functional layers 12 and 13, or applying such a solution to the waste film 1. When immersing the waste film 1 in the solution, a method that more efficiently removes the functional layers 12 and 13 may be used, such as shredding the waste film 1 beforehand or stirring it together with the media (abrasive material) while immersing it in the solution.

[0044] In the second processing apparatus 50, the waste film 1 may be heat-treated and thermally shrunk during the process of removing the functional layers 12 and 13. For example, the waste film 1 may be heated and thermally shrunk before removing the functional layers 12 and 13. In this case, since the waste film 1 becomes thicker before removing the functional layers 12 and 13, even if tension is applied to the waste film 1 when removing the functional layers 12 and 13, it is possible to prevent the waste film 1 from breaking. The heat treatment referred to here includes clamping the waste film 1 with heating rollers, immersing it in hot water, passing it through a hot air tunnel, and blowing steam onto it. The set temperature for the heat treatment varies depending on the heating method, but for example, when immersing in hot water, 70°C to 100°C is preferred, and 80°C to 95°C is preferred.

[0045] The waste film 1 (i.e., processed film 2) from which the functional layers 12 and 13 have been removed in the second processing apparatus 50 is then wound up by the winding machine 62 to become a film roll R2. The film roll R2 is then supplied to the manufacturing apparatus 20, where recycled resin raw material 3 is produced.

[0046] [3. Features] In the above embodiment, recycled resin raw material 3 is manufactured using waste film 1 from which the splice tape 5 has been removed as a starting material. Therefore, recycled resin raw material 3 with less foreign matter contamination can be manufactured. Consequently, recycled film 4 with less foreign matter contamination can be manufactured using such recycled resin raw material 3.

[0047] Furthermore, in the above embodiment, the break in the waste film 1 caused by the removal of the splice tape 5 is reconnected by the sealer 430. Therefore, even after the splice tape 5 is removed, the resin film can be efficiently processed while being transported roll to roll.

[0048] Furthermore, in the above embodiment, the break in the waste film 1 caused by the removal of the splice tape 5 is reconnected by joining it with resin tape 6. Therefore, it is possible to suppress the inclusion of new foreign matter into the processed film 2, which is used as the starting material for the recycled resin raw material 3.

[0049] [4. Variant] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. For example, the following modifications are possible. Furthermore, the gist of the following modifications can be combined as appropriate.

[0050] [4-1] The method for removing the splice tape 5 from the waste film 1 is not limited to the example described above. For example, the splice tape 5 may be automatically peeled off by grasping its end and pulling it.

[0051] [4-2] The method for connecting the disconnected parts in the waste film 1 is not limited to the method described above (ultrasonic sealing), but may also be done by high-frequency sealing, heat sealing, or solvent sealing.

[0052] [4-3] In the above embodiment, the broken portion of the waste film 1 was joined with resin tape 6, but it may be joined without using resin tape 6. For example, the portion near the upstream separation end and the portion near the downstream separation end of the waste film 1 separated by the removal of the splice tape 5 may be overlapped, and the overlapped portion may be directly bonded (welded). In this case, it is preferable to seal the portion near the upstream separation end and the portion near the downstream separation end of the waste film 1 in a dashed line (perforated line) rather than a straight line so that it does not tear. The overlapping portion near the upstream and downstream separation ends of the waste film 1 may be bonded (welded) in two or more places (two or more rows).

[0053] Alternatively, as shown in Figure 5, the waste film 1 may be left loose near the area where the splice tape 5 is attached along the MD (see Figure 5(A)). The splice tape 5 may then be removed from the waste film 1 by clamping the area near the base of the loose portion 1a with a pair of welding heads 7 and bonding (welding) it (see Figure 5(B)), and simultaneously cutting off the removal portion 1b outside the bonded (welded) area of ​​the loose portion 1a with a cutting blade 8 (see Figure 5(C)). In this case, bonding (welding) may be performed in a straight line or in a dashed line (perforated line). Bonding (welding) may be performed in two or more places (two or more rows). The removal portion 1b may be cut off simultaneously with bonding (welding) by ultrasonic sealing or the like.

[0054] [4-4] In the above embodiment, the broken sections in the waste film 1 were reconnected. However, the waste film 1 may be collected in its broken state without reconnecting the broken sections, and this may be used as the starting material to manufacture the recycled resin raw material 3. In this case, the removal of the splice tape 5 may be performed after the functional layers 12 and 13 have been removed from the waste film 1.

[0055] [4-5] In the above embodiment, an example is shown in which the functional layer is laminated on both the front and back surfaces of the film body 11. However, the functional layer may be laminated on only one surface of the film body 11. That is, one of the functional layers 12 and 13 may be omitted. In this case, it is preferable that the resin tape 6 is superimposed on the surface of the film body 11 that does not have a functional layer laminated on it, and then bonded (welded) to it, so as not to interfere with the removal of the functional layer by the second processing apparatus 50 in the subsequent stage.

[0056] [4-6] In the above embodiment, an example using a sheet-like waste film 1 is shown, but the waste film 1 may also be a long, tubular film before it is attached to a container. When the tubular waste film 1 is wound onto the film roll R1, it is folded flat. The tubular waste film 1 unwound from the film roll R1 may be cut longitudinally and unfolded into a sheet, after which the splice tape 5 may be removed by the removal device 10. Alternatively, the splice tape 5 may be removed from the waste film 1 while it is still in its tubular form after being unwound from the film roll R1. After the splice tape 5 is removed, the upstream and downstream separated ends of the separated waste film 1 may be connected with or without the resin tape 6. Furthermore, multiple tubular waste films may be connected while remaining in their tubular form. In this case, it is preferable that the multiple tubular waste films are connected with the sealed portion (the portion where the overlapping ends of the TD of the sheet-like film are sealed to the MD when the waste film is formed from a sheet to a tubular shape) aligned along the TD. [Explanation of symbols]

[0057] 1. Waste film 1a. Slack area 1b Removed part 11 Film body 12, 13 Functional Layers 2. Processed film 3 Recycled resin raw materials 3a Fluff 3b Pellet 3c powder 3d granules 4. Recycled film 5 Splice Tape 6. Resin tape 7 Welding head 8 cutting blades 10 Removal device 20. Manufacturing equipment for recycled resin raw materials 30 Film manufacturing equipment 40 1st processing device 410 Detection unit 420 Cutting Machine 421,422 Retaining mechanism 430 Sealer 50 Second processing device 60 Guide Rollers 61 Unwinding machine 62 Winder 70 Accumulator 100 Control Unit S1 Resource Recycling System R1, R2 film rolls

Claims

1. Prepare a roll of resin film joined with splice tape, The process of unwinding the resin film from the roll, Removing the splice tape from the resin film unwound from the roll, The process involves removing the printed layer contained in the resin film from which the splice tape has been removed, The resin film from which the printing layer has been removed is used as a starting material to produce recycled resin raw material. A method for producing recycled resin raw materials, including those mentioned above.

2. The separated ends of the resin film, separated by the removal of the splice tape, are connected. It further includes, Removing the printed layer means removing the printed layer from the resin film to which the separated ends are connected. A method for producing recycled resin raw materials according to claim 1.

3. Connecting the aforementioned separation ends includes joining the aforementioned separation ends with a resin tape. A method for producing recycled resin raw materials according to claim 2.

4. The resin film and the resin tape are heat-shrinkable films. A method for producing recycled resin raw materials according to claim 3.

5. Removing the aforementioned splice tape is The position of the splice tape contained in the resin film is detected, Based on the detected position, the splice tape is removed from the resin film. including, A method for producing recycled resin raw materials according to any one of claims 1 to 4.

6. The splice tape is aluminum tape or colored vinyl tape. A method for producing recycled resin raw materials according to any one of claims 1 to 4.

7. A recycled film is manufactured using the recycled resin raw material produced by the manufacturing method described in any one of claims 1 to 4 as at least a part of the raw material. A method for manufacturing recycled film, including the following.

8. A dispensing unit that dispenses the resin film from a roll on which the resin film, joined with splice tape, is wound, A removal unit for removing the splice tape from the resin film unwound from the roll, A deinking section for removing the printed layer contained in the resin film from which the splice tape has been removed. A processing apparatus for resin films, equipped with the following features.

Images